The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Compressors are used in a wide variety of industrial and residential applications to circulate refrigerant within a refrigeration, heat pump, HVAC, or chiller system (generically referred to as “refrigeration systems”) to provide a desired heating and/or cooling effect. In any of the foregoing applications, the compressor should provide consistent and efficient operation to ensure that the particular refrigeration system functions properly.
Refrigeration systems and associated compressors may include a protection device that intermittently restricts power to the compressor to prevent operation of the compressor and associated components of the refrigeration system (i.e., evaporator, condenser, etc.) when conditions are unfavorable. For example, when a particular fault or failure is detected within the compressor, the protection device may restrict power to the compressor to prevent operation of the compressor and refrigeration system under such conditions.
The types of faults that may cause protection concerns include electrical, mechanical, and system faults. Electrical faults typically have a direct effect on an electrical motor associated with the compressor, while mechanical faults generally include faulty bearings or broken parts. Mechanical faults often raise a temperature of working components within the compressor and, thus, may cause malfunction of, and possible damage to, the compressor.
In addition to electrical and mechanical faults associated with the compressor, the refrigeration system components may be affected by system faults attributed to system conditions such as an adverse level of fluid disposed within the system or to a blocked-flow condition external to the compressor. Such system conditions may raise an internal compressor temperature or pressure to high levels, thereby damaging the compressor and causing system inefficiencies and/or failures. To prevent system and compressor damage or failure, the compressor may be shut down by the protection system when any of the aforementioned conditions are present.
Conventional protection systems may sense temperature and/or pressure parameters as discrete switches to interrupt power supplied to the electrical motor of the compressor should a predetermined temperature or pressure threshold be exceeded. Such systems typically employ multiple temperature and pressure sensors to detect operating parameters of the compressor, which results in a complex and costly protection system.
Because conventional protection systems directly control a compressor to which they are tied, conventional protection systems cannot be used with multiple control modules, and may only be used with a single compressor and a single controller.